1. Field of the Invention
The present invention relates to an antenna provided at an insertion port, through which a non-contact type communication medium is inserted. Further, the invention relates to a non-contact type communication medium processing unit provided with such antenna in order to read information stored in a non-contact type communication medium by means of non-contact type communication.
2. Description of the Related Art
JP-A-2001-118035 (FIGS. 1 and 3) describes an IC card reader that takes in a non-contact type IC card and communicates with the card to perform processing of card information. The IC card reader is provided at its insertion port with a communication coil for card detection in order to prevent a card, which is incapable of non-contact communication, from being taken into the IC card reader. A surface of the coil is arranged in parallel to a card surface of a non-contact type IC card. That is, a plane defined by a coil of a coil antenna in the non-contact type IC card and a plane defined by a coil of the communication coil for card detection are made parallel to each other. A shutter is provided between the insertion port and an interior of the IC card reader. When a non-contact type IC card is inserted into the insertion port, the communication coil for card detection detects presence of the non-contact type IC card. On the basis of such detection, the IC card reader opens the shutter. Without such detection, the IC card reader maintains the shutter in a closed state. Thereby, the IC card reader prevents taking-in of a card, which is incapable of non-contact communication. When the IC card reader opens the shutter, the IC card reader operates a card conveyance mechanism to take in a non-contact type IC card. The IC card reader is provided therein with a card-reader side communication coil. The card-reader side communication coil performs non-contact type communication with the taken in non-contact type IC card. Thereby, the IC card reader reads information of the non-contact type IC card.
JP-A-6-139416 (FIGS. 1 and 5) describes a data processing unit commonly usable for a contact type card such magnetic cards, contact type IC cards, etc. and a non-contact type IC card. The data processing unit is provided with a card insertion port. A contact type card is inserted into the insertion port. The data processing unit reads information of the contact type card therein. The data processing unit is provided in the vicinity of the insertion port with a single loop-shaped antenna. When a non-contact type IC card approaches the insertion port in a manner to make its card surface parallel to an antenna surface, the loop-shaped antenna reads information from the non-contact type IC card.
JP-UM-A-7-20662 (FIGS. 1 and 3) describes an automatic ticket checker for preventing the breakage of a mechanism for conveying a magnetic ticket and a non-contact type ticket when the non-contact type ticket is inserted into an insertion port, into which a magnetic ticket should be inserted. The automatic ticket checker is provided on an upper surface of its body with a first antenna for communication with a non-contact type ticket. On the basis of information of a non-contact type ticket obtained from the first antenna, the automatic ticket checker permits or inhibits entrance/exit of a user having a non-contact type ticket. The automatic ticket checker is provided at the insertion port with a shutter. The shutter is normally put in an opened state. When a contact-type ticket is inserted into the insertion port, the conveyance mechanism is operated to take in the contact-type ticket to read information thereof. On the basis of the read information, the automatic ticket checker permits or inhibits entrance/exit of a user having the contact type ticket. The automatic ticket checker is provided in the vicinity of the insertion port with a second antenna that communicates with a non-contact type ticket. When a non-contact type ticket approaches the insertion port, the second antenna detects approach of the non-contact type ticket. In order to prevent a non-contact type ticket from being erroneously inserted into the insertion port, the automatic ticket checker closes the shutter.
JP-A-2000-132646 (FIGS. 1 and 4) describes a card reader capable of reading information from a magnetic card, a contact type IC card, and a non-contact type IC card in a short time. When a non-contact type IC card is inserted into an insertion port of the card reader, the card reader reads information of the non-contact type IC card by means of an antenna provided at the insertion port. Thereby, a period of time for conveying the non-contact type IC card is shortened. When a contact type IC card is inserted into the insertion port of the card reader, the card reader has an IC contact unit, which is provided at the insertion port, contacting with the contact type IC card. Then, the card reader reads information from the contact type IC card. Thereby, a period of time for conveying the contact type IC card is shortened. When the card reader judges that a card is neither a non-contact type IC card nor a contact type IC card, the card reader conveys the card inside thereof. Then, a magnetic head is used to read information.
JP-A-2000-172794 (FIG. 1) describes a non-contact card system that reads information of a non-contact type IC card. Two coil antennas are provided on U-shaped, opposed inside walls in a frame that is U-shaped in cross section. A first coil antenna surface and a second coil antenna surface are opposed to each other. When a non-contact type IC card enters a space defined by the two coil antenna surfaces, the non-contact card system communicates with the non-contact type IC card.
JP-A-2003-99730 (FIG. 1); JP-A-8-330838 (FIGS. 1 and 3); JP-A-11-316805 (FIG. 2); JP-A-7-30319 (FIG. 3) describe loop antennas for enhancement of communication performance. The loop antennas comprise two continuous coil antennas. A first coil antenna is wound clockwise. A second coil antenna is wound counterclockwise.